Indoor cultivation of fruits, vegetables, flowers and ornamental plants is an increasingly popular method of producing living plants, whether for the horticulturist, hobbyist or professional nursery operator. In some operations, seeds are planted in flat, plant growing trays and these trays are exposed to light and watering conditions optimized for growth. Typically, these planting trays are arrayed in an open area and watered using a large spraying system which is adapted to provide fairly uniform watering over the entire open area. This introduces two factors of concern, the first being wastage of water sprayed between trays and typically not recovered, the second being maintaining operation of a large water pumping system so that optimum watering conditions are maintained. Another factor is providing different watering conditions that are optimized to meet the requirements of different plants.
U.S. Pat. No. 5,673,511 describes a self-watering tray for supporting and displaying a plurality of potted plants which can be watered from a water reservoir in the bottom of the tray, the tray comprising a plurality of wall sections which define spaced openings in the tray, each wall section being provided with a support located above the reservoir for supporting the potted plant at or above the water, and being laterally open to the adjacent wall sections below the supports to provide a continuous reservoir channel below the supports and pots, through which water can circulate for watering plants by capillary action.
U.S. Pat. No. 5,425,198 discloses a device for automatically watering potted type plants has a shallow reservoir base/tray capable of holding water and also capable of supporting at least one previously potted plant and also capable of supporting an inverted container, such as a typical screw top jar turned upside down, for containing additional water and/or other plant nutrients. A specially adapted support base is used to keep the bottom of the inverted container where the opening is located slightly above the bottom of the base/tray. The base/tray can have ribs or rails to keep the potted plant raised slightly above the lowest part of the tray but lower than the opening in the inverted container. The water container has a detachable lid with a hole. The detachable lid is attached to the water filled container not yet inverted and the lid and container are fixed to the base/tray while the hole is covered by the plant owner's finger creating a partial vacuum in the water container such that water will only flow from the water container when the water level in the tray/base drops below the level of the inverted container opening.
U.S. Pat. No. 5,247,762 claims a controlled release hydraulic watering system for either an individual plant pot or for a plurality of potted plants. The system utilizes a porous terra cotta water-receiving reservoir which, through permeation, can distribute water either into an individual potted plant at a controlled release rate without over-watering the plant contained therein or onto a capillary sheet and horticultural matting used in an irrigating tray containing a plurality of potted plants providing a proper amount of water to the tray for watering all the plants contained therein. The terra cotta reservoir may include an exterior side wall covering of horticultural matting, silica sand and a plastic sheet.
U.S. Pat. No. 5,179,800 entails a plant growing tray system which includes a tray with a plurality of individual plant cells having an open top and bottom and a detachable screen or perforated bottom. Each tray cell is designed to contain and hold a plant growing medium such as peat cake or peat-soil mix. A detachable bottom secured to the bottom part of the plant tray provides air pruning of plant roots and can be conveniently removed from the plant tray for easy removal of the individual plants or seedlings from the tray bottom. Air-pruning of plant roots eliminates root binding or tangling and accelerates root branching resulting in enhanced plant growth in the cell or after transplanting. The plant tray has a surrounding edge to hold a water level above the top of the tray cell or micro-feeding holes of each cell for self watering and to maintain uniform root zone temperature throughout the tray. The detachable screen or perforated bottom can be press fitted to the tray bottom to hold the peat mix and to provide effective air-pruning of the plant roots.
U.S. Pat. No. 4,106,235 discloses a portable planter for house plants comprising an upper plant holder means received in a lower vessel containing water for the plant such that the lower vessel is effectively closed to prevent loss of water vapor, the water level being below the bottom of the plant holder means, the bottom of said plant holder means including a support means comprising crossing reinforcing ribs supporting a removable aluminum window screen, said bottom being at least 34% open and holding fine particulate plant-supporting material at least directly on said screen and accommodating a substantial root system, said screen having openings at least 1/36 inch and smaller than about 150 inch in the largest dimensions.